Telecommunications Hyperspectral Imaging Devices

Telecommunications Applications

With carrier spending under increasing scrutiny, modern global communications systems continue to advance toward an "all-optical" network.

As new carrier services create additional sources of traffic, there remains greater economic justification for carriers to look for innovative, cost effective ways to push more data through existing fiber.

System providers and network component suppliers continue to explore new solutions and refine the network elements required for carriers to deploy new services at reduced costs. Utilization of optical network elements - utilizing wavelength solutions - reduces the cost and complexity of expanding and maintaining communication networks.

Optical technologies and optical subsystems utilizing bulk diffraction gratings represent key building blocks enabling the economic advantages and flexibility of an all optical network. Tools such as Optical Spectrum Analyzers, Gain Equalizers and Tunable Lasers currently use diffraction grating technology. Developers of telecommunication equipment involved in the separation or combining of wavelengths such as in Optical Switching or Coarse/Dense Wavelength Division Multiplexing (CWDM/DWDM) are re-evaluating the use of arrayed waveguides, fiber bragg gratings and thin film filters in favor of the more efficient solutions offered by holographic low PDL holographic diffraction gratings.

Headwall Photonics' spectral modules and original diffraction gratings have the high efficiency, low stray light, and uniform, quality performance that our Telecommunications customers require and depend on. As a new venture, we have unique strengths - Headwall Photonics' rich legacy of American Holographic original diffraction grating technology coupled with the manufacturing process discipline of Agilent Technologies and a superior infrastructure yields high volume, accurate and consistent high quality products. We work collaboratively to develop optical wavelength solutions that meet your requirements.

DWDM/CWDM

Wavelength Division Multiplexing (WDM) is the transmission of multiple close-spaced wavelengths or channels through the same fiber. Dense WDM (known as DWDM) was originally designed for long-haul transmission, where Erbium Doped-Fiber Amplifiers (EDFAs) are needed at intervals to boost the power of the light. EDFAs work over only a fairly narrow range of frequencies, known as the C- and L-bands (between 1530 and 1620 nanometers). The impact is that wavelengths have to be packed tightly together. Course WDM (known as CWDM) was designed for shorter distances, where EDFAs aren't required. As a result, it uses a much wider range of frequencies - 1270 to 1610 nm - and it spreads the wavelengths around 20nm apart. Coarse WDM is being seen as a simple, cost-effective alternative to Dense WDM systems.

Regardless of the number of channels or spacing, the use of Bulk Diffraction Grating technology for the multiplexing/demultiplexing (mux/demux) in WDM systems is gaining wider acceptance. As one of the most mature technologies for separating wavelengths on the market, bulk diffraction gratings have numerous advantages over arrayed-waveguide gratings (AWGs), Thin-Film Filters (TFF) and Fiber Bragg Gratings (FBG). Identified for their Gaussian-shaped pass-band, diffraction grating based components produce the lowest insertion loss at the pass-band center wavelength. Recent developments in grating technology have greatly enhanced performance characteristics in cross talk reduction, polarization-dependent loss and size.

Headwall Photonics is a leading supplier of high volume original holographic diffraction gratings for the telecommunications industries. Headwall Photonics discovered that the highest performance originates from mastering our patented fabrication techniques. Our novel approach and proprietary technologies results in gratings characterized by:

  • High efficiency
  • Low stray light
  • Excellent signal/noise ratios
  • Low polarization-dependent loss performance

A rich legacy of American Holographic technology coupled with the manufacturing process discipline of Agilent Technologies has enhanced our core competencies of high volume, precision manufacturing, optical design service, and collaborative engineering support. Our superior infrastructure and process controls provide cost-effective, repeatable, reliable and consistent high quality products (ISO 9001:2008 certification).

Headwall Photonics is known for its ability to rapidly design and prototype complex gratings for demanding applications. We are a leader in nanostructure manufacturing offering high efficiency, low polarization-dependent loss and low stray light gratings and modules in the smallest form factor available. Engineers at Headwall Photonics have the spectral module expertise to assist you in creating the proper alignment of the components necessary for the development of innovative multiplexers for DWDM and CWDM systems. Our high level engineering architecture and knowledgeable scientists and engineers become a strategic extension of your engineering team, working collaboratively to develop cost-effective optical wavelength solutions.

Optical Spectrum Analysis

Field deployment of DWDM systems with high count, closely spaced channels has led to the development of a new generation of optical spectrum analyzers (OSAs). OSAs provide exact wavelength, power level, and the dynamic range for each wavelength/channel in a DWDM system. OSAs can be deployed either as portable test systems, embedded systems to be incorporated in the DWDM transmission systems (sometimes referred to as Channel Monitors), or as bench-top instrumentation for DWDM system characterization. Optical spectrum analyzers are ideal instruments for laser modes analysis, very high-resolution spectroscopic measurements, telecommunication device and system tests and other applications.

There are three different optical spectrum analyzer designs that can be used in the field: interferometric, the Fabry-Perot method and the diffraction grating method. Today, the majority of deployed bench top and field portable spectrum analyzers consist of a mechanically scanned double-pass or four-pass grating monochromator, while embedded systems utilize a Fabry-Perot filter as the tuning element. The capabilities of each method are based on several important characteristics:

  • Spectral resolution
  • Wavelength accuracy
  • Dynamic range
  • Polarization sensitivity
  • Channel selection characteristics.

Performance realized utilizing diffraction grating methods is mainly dependent on the quality of the gratings being used. Off-the-shelf, replicated gratings do not have the polarization sensitivity, high resolution and wavelength accuracy needed for top-quality instruments. For these applications, original holographic gratings are required.

Headwall Photonics discovered that the highest performance originates from mastering fabrication techniques. Our novel approach and proprietary technologies result in High Efficiency, Low Stray Light, Excellent Signal/Noise Ratios and Low Polarization-Dependent Loss performance in a single component. Headwall Photonics is a leading supplier of high volume original holographic diffraction gratings for the telecommunications industries. A rich legacy of American Holographic technology coupled with the manufacturing process discipline of Agilent Technologies has enhanced our core competencies of high volume, precision manufacturing, optical design service, and collaborative engineering support. Our superior infrastructure and process controls provide cost-effective, repeatable, reliable and consistent high quality products. (ISO 9001:2008 certification)

Headwall Photonics is known for its ability to rapidly design and prototype complex gratings for demanding applications. We are a leader in nanostructure manufacturing offering high efficiency, low polarization-dependent loss and low stray light gratings and modules in the smallest form factor available. Engineers at Headwall Photonics have the spectral module expertise to assist you in creating the proper alignment of the components necessary for the development of innovative OSAs. Our high level engineering architecture and knowledgeable scientists and engineers become a strategic extension of your engineering team, working collaboratively to develop cost-effective optical wavelength solutions.

Channel Monitoring / Gain Equalization

In next generation networks, service providers will need to have much better control over gain given that amplifiers will be accommodating a varying number of wavelengths and signal power. Today's solution is to employ fixed gain-flattening filters (FGFFs), which apply a fixed and pre-set attenuation. This creates a problem in that FGFFs are not sophisticated enough to handle the varying power fluctuations that will be considered normal across all optical networks. One of the key solutions to this problem will be the introduction of dynamic gain equalizers (DGEs).

DGEs correct or equalize the imbalances in the power of signal channels. Over the last few years, DGE manufacturers have used several technological approaches:

  • Micro-electromechanical systems (MEMs)
  • Diffractive MEMs
  • Liquid crystals
  • Silica waveguides
  • Fiber Bragg Gratings (FBG)

As the telecom technologies continue to consolidate, keys to the success of the devices remaining will be high resolution, solid-state devices with no moving parts, low insertion loss, and low PDL. Those hybrid products made with diffraction gratings meet all these requirements.

Headwall Photonics is a leading supplier of high volume original holographic diffraction gratings for the telecommunications industries. We have discovered that the highest performance originates from mastering fabrication techniques. Our novel approach and proprietary technologies result in both High Efficiency and Low Polarization-Dependent Loss performance in a single component. Test results show the reliability of our gratings in accordance with Telcordia GR-1221-CORE, Generic Reliability Assurance, Requirements for Passive Optical Components. Our superior infrastructure and process controls provide repeatable, reliable and consistent high quality products. (ISO 9001:2008 certification)

Headwall Photonics is known for its ability to rapidly design and prototype complex gratings for demanding applications. A rich legacy of American Holographic technology coupled with the manufacturing process discipline of Agilent Technologies has enhanced our core competencies of high volume, precision manufacturing, optical design service, and collaborative engineering support. We are a leader in nanostructure manufacturing offering high efficiency, low polarization-dependent loss and low stray light gratings and modules in the smallest form factor available. Our high level engineering architecture and knowledgeable scientists and engineers become a strategic extension of your engineering team, working collaboratively to develop cost-effective optical wavelength solutions.

Optical Switching

Most internetworking equipment today is based on electronic-signaling; the impact being that the optical signals have to be converted to electrical ones, become amplified, regenerated and switched, and then reconverted to optical signals. This is generally referred to as an 'optical-to-electronic-to-optical' (OEO) conversion and is a significant bottleneck in communication transmission. The basic premise of optical switching is that by replacing existing electronic network switches with optical ones, the need for OEO conversions is minimized. Clearly, the advantages of being able to avoid the OEO conversion stage are significant. First, optical switching is less costly, as there is reduced need for expensive high-speed electronics. Removing this complexity also allows for physically smaller switches to be manufactured. These "all-optical" devices utilize mirrors, holographic gratings, LCDs, digital optics, and other emerging technologies to direct light between ports.

Unfortunately, optical switching technology is still very much in its infancy due to carriers cutting back on deployment and capital spending. As carriers determine how to reduce expenses and generate immediate profits, optical switch vendors are busy refining and improving their technology, and researching other applications utilizing optical switch technology outside of telecommunication (i.e. projection displays as communication aids for the disabled).

Headwall Photonics is a leading supplier of high volume original holographic diffraction gratings for the telecommunications industries. Headwall Photonics discovered that the highest performance originates from mastering fabrication techniques. Our novel approach and proprietary technologies result in High Efficiency, Low Stray Light, Excellent Signal/Noise Ratios and Low Polarization-Dependent Loss performance in a single component. A rich legacy of American Holographic technology coupled with the manufacturing process discipline of Agilent Technologies has enhanced our core competencies of high volume, precision manufacturing, optical design service, and collaborative engineering support. Our superior infrastructure and process controls provide cost-effective, repeatable, reliable and consistent high quality products. (ISO 9001:2008 certification)

Headwall Photonics is known for its ability to rapidly design and prototype complex gratings for demanding applications. We are a leader in nanostructure manufacturing offering high efficiency, low polarization-dependent loss and low stray light gratings and modules in the smallest form factor available. Engineers at Headwall Photonics have the spectral module expertise to assist you in creating the proper alignment of the components necessary for the development of innovative optical switches. Our high level engineering architecture and knowledgeable scientists and engineers become a strategic extension of your engineering team, working collaboratively to develop cost-effective optical wavelength solutions.

Tunable Lasers

Among the most promising developments in optical components is tunability, which allows lasers, filters and other components to adjust to particular wavelengths. Tunable lasers have the ability to solve logistical problems for carriers, such as reducing the need for spares, enabling automated network provisioning, and increasing flexibility for new service offerings without additional costs. Tunable lasers should ideally offer the same reliability, spectral quality, and cost as the fixed-wavelength distributed feedback lasers that they are designed to replace. Manufacturers of tunable lasers must also face the challenge of manufacturing high performance, reliable components in high volume.

Although internetworking standards exist for communication protocols, electrical interfaces, power supplies and mechanical form standards, there is still a great deal of variability in the technology of tuning. One parameter not yet specified is optical performance. External Cavity Lasers (ECL), Modified Distributed Bragg Reflectors (i.e. Sampled-Grating DBR, Digital Supermode DBR and Superstructure-Grating DBR), and even some Vertical Cavity Surface Emitting Lasers (VCSEL) all use some form of gratings, but performance and spectral quality differ greatly.

Headwall Photonics is a leading supplier of high volume original holographic diffraction gratings for the telecommunications industries. We have discovered that the highest performance originates from mastering fabrication techniques. Our novel approach and proprietary technologies result in both High Efficiency and Low Polarization-Dependent Loss performance in a single component. Test results show the reliability of our gratings in accordance with Telecordia GR-1221-CORE, Generic Reliability Assurance, Requirements for Passive Optical Components. Our superior infrastructure and process controls provide repeatable, reliable and consistent high quality products. (ISO 9001:2008 certification)

Headwall Photonics is known for its ability to rapidly design and prototype complex gratings for demanding markets such as telecommunication applications. A rich legacy of American Holographic technology coupled with the manufacturing process discipline of Agilent Technologies has enhanced our core competencies of high volume, precision manufacturing, optical design service, and collaborative engineering support. We are a leader in nanostructure manufacturing offering high efficiency, low polarization-dependent loss and low stray light gratings and modules in the smallest form factor available. Our high level engineering architecture and knowledgeable scientists and engineers become a strategic extension of your engineering team, working collaboratively to develop optical wavelength solutions.

For a more detailed discussion of your application-specific requirements, please contact us.